Bone changes in thyrotoxicosis

: Thyroid hormone (T3) is essential for normal bone growth and bone metabolism. T3 stimulates bone formation directly through T3 receptors in osteoblasts. T3 also stimulates bone resorption by osteoclasts probably secondary through osteoblasts. In thyrotoxicosis accelerated bone formation and resorption resulted in high turn-over bone loss. Bone metabolic markers elevate reflecting thyrotoxic state. Normalizing thyroid hormone level at least partially restore bone mineral content. In patients under thyroid hormone replacement therapy or TSH suppression therapy TSH and free thyroid hormones should be monitored to prevent unnecessary bone loss. Especially in postmenopausal women with thyrotoxicosis or thyroid hormone therapy the assessment of bone mineral content is required.